#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>

int main()
{
    int n = 0, h = 0, m = 0;
    scanf("%d %d %d", &n, &h, &m);
    int tmp = m / h;
    if (m % h != 0)
    {
        tmp++;
    }
    if (n > tmp) printf("%d", n - tmp);
    else printf("%d", 0);
    return 0;
}